The present invention relates to a new and improved construction of a solar thermal power plant.
Generally speaking, the solar thermal power plant of the invention is of the type comprising a radiation receiver installed at a tower or column and a heliostat field whose mirrors or reflectors direct the incident solar radiation in a concentrated or focused manner upon the radiation receiver. Also, there is provided a hot water storage for the storage of the work medium which is heated to the operating temperature and devices serve for the thermal charging and discharging of the hot water storage.
With the heretofore known power plants of this type, which also are designated as column or tower designs, there are employed mirrors or reflectors which are controlled as a function of the position of the sun. The totality of these mirrors or reflectors form a heliostat field and direct the solar radiation in a concentrated fashion onto a radiation receiver installed at a tower. The radiation receiver contains absorber elements which convert the received radiation into thermal energy or heat and deliver such to a work medium which is circulated through a pipe system. The absorber elements are generally internally blackened hollow bodies open at one side and through whose opening there can arrive the concentrated radiation beam. They form an almost ideal black body, so that practically the entire incident radiation is utilized for generating heat. The work medium transports the heat which has been taken-up to steam generators installed at the ground, which supply in conventional fashion turbo-generators for generating electrical energy.
The efficiency of the collector system composed of the heliostat field and the radiation receiver, apart from being dependent upon the temperature of the radiation receiver, markedly depends upon the degree of concentration of the radiation at the receiver. It increases to a great degree as a function thereof, so that there are strived for high degrees of concentration which, however, require large and heavy receivers.